The present disclosure, for example, relates to communications systems, and more particularly to linearizing signals in a radio frequency (RF) communications system.
Transmitters and receivers of a RF communications system may employ amplitude and phase modulation of a signal. The signal being modulated may become distorted in the transmitter or receiver due to various factors. For example, components of the transmitter or receiver may experience non-linear behaviors when first switched on. The non-linear behavior of the components may cause amplitude and phase distortion of the signal. The amplitude and phase distortion may result in less reliable or slower communication between the transmitter and receiver, as the communication may be dependent upon accurate amplitude and phase modulation.
The phase and amplitude of the signal may be adjusted in the transmitter or receiver to overcome the distortion. For example, the phase and amplitude of the signal may be shaped so that a resulting signal exhibits linear amplitude and phase characteristics. A signal having linear amplitude and phase characteristics may allow for improved reliability and speed of communications between the transmitter and receiver.
Conventional approaches for shaping phase and amplitude may involve complex pre-distortion or feedback schemes to overcome the non-linear behavior of the components of the transmitter or receiver. In these approaches, the shaping of the amplitude and phase may be coupled. A change in amplitude may result in a change in phase, and a change in phase may result in a change in amplitude. This coupling may cause increased difficulty in maintaining both linear amplitude and linear phase at the same time. Therefore, it may be expensive and difficult to overcome the phase and amplitude distortion in transmitters and receivers.